Vacuum Processing Apparatus And Vacuum Processing Method

ABSTRACT

A vacuum processing apparatus includes vacuum processing chambers for subjecting a sample to vacuum processing, a vacuum carriage, a switchable chamber, a cassette support for supporting a plurality of cassettes capable of housing samples, and a waiting cassette support for supporting a waiting cassette that differs from the cassettes supported on the cassette support and capable of having a number of samples. An atmospheric carriage enables carrying a sample among a given cassette of the plurality of cassettes or the waiting cassette. A controller effects control for carrying unprocessed and processed samples among the given cassette, the waiting cassette and the vacuum processing chamber, so that a mixture of both processed and unprocessed samples does not exist in the given cassette or the waiting cassette.

This application is a continuation of U.S. application Ser. No.12/230,466, filed Aug. 29, 2008, which is a continuation of U.S.application Ser. No. 10/874,241, filed Jun. 24, 2004, now U.S. Pat. No.7,476,073, the contents of which are incorporated herein by reference.This application relates to U.S. application Ser. No. 12/230,467, filedAug. 29, 2008, now U.S. Pat. No. 7,862,289, which is a continuation ofU.S. application Ser. No. 10/874,241, filed Jun. 24, 2004, now U.S. Pat.No. 7,476,073.

The present application claims priority from Japanese patent applicationNo. 2004-097774 filed on Mar. 30, 2004, the content of which is herebyincorporated by reference into this application.

FIELD OF THE INVENTION

The present invention relates to a vacuum processing apparatus andvacuum processing method equipped with plural vacuum processingchambers, and more specifically, to the improvement of yield factor andoperating rate of the vacuum processing apparatus and method that usecorrosive gas such as halogen gas.

DESCRIPTION OF THE RELATED ART

Heretofore, the operating rate of a vacuum processing apparatus using atleast two sets of processing devices was enhanced by utilizing theprocessing chambers that are operating normally as the processing pathwhen any of the processing chambers is out of order due to malfunctionetc. during operation (refer for example to patent document 1).

In an apparatus having a post-processing chamber or where the etchedwafer carried out of the processing chamber is released directly toatmosphere, the wafer was subjected to ashing treatment or heatingtreatment, but there was no sufficient consideration on how to enhancethe yield factor of the apparatus by reducing the residual gas on thesurface of the wafer. If the processing of a specific device did notallow ashing treatment or heating treatment to be performed, the devicehad to be carried out of the chamber without being subjected to suchtreatment. The residual gas on the surface of the processed wafer beingstored in a carrier such as a FOUP (front opening unified pod) afteretching causes foreign matter to be attached to the unprocessed wafer,and the foreign matter considered to be caused by halogen gas on thewafer act as mask during etching treatment, which may cause etchingresidue or the like that deteriorate the yield factor. Furthermore,since the residual gas could not be removed completely, the increase ofresidual gas concentration in the FOUP or other carriers affecting thesurrounding environment has become a problem.

There has been proposed a batch vacuum processing system adopting athird cassette disposed along the path of carriage of the wafers thatenables the wafers to be returned to its original position in thecassette (refer for example to patent document 2). However, there is nodisclosure of an art that prevents mixture of the unprocessed samplesand processed samples by putting either the unprocessed or processedsamples in waiting.

Patent Document 1:

-   Japanese Patent Application Laid-Open No. 2001-93791

Patent Document 2:

-   Japanese Patent Application Laid-Open No. 62-216315

According to the prior art, the processed wafers (processed samples) andthe unprocessed wafers (unprocessed samples) were stored in a mixture ina single carrier such as a FOUP, which caused deterioration of the yieldfactor of the product due to the foreign matter or the like derived fromthe processed wafers. The object of the present invention is to providea vacuum processing apparatus and vacuum processing method capable ofimproving the yield factor of the product.

SUMMARY OF THE INVENTION

In order to achieve the above object, the present invention adopts awaiting station to be disposed within an atmospheric carriage unit forpreventing the unprocessed wafers from being mixed with the processedwafers in a single carrier. The term “waiting station” is used as ageneric term including a waiting cassette disposed in atmosphere and awaiting chamber disposed in vacuum. Further, the waiting station can beequipped with a purging system for enhancing the substitution of theresidual containing gas derived from the processed wafers. Moreover, theunprocessed wafers can be carried into the waiting station while theprocessed wafers are carried to the original carrier.

Moreover, the present invention optimizes carriage sequence for reducingthe effect to the throughput caused by the addition of the waitingstation.

The present invention provides a vacuum processing apparatus comprisinga plurality of vacuum processing chambers for subjecting a sample tovacuum processing, a vacuum carriage means for carrying the sample intoand out of the vacuum processing chamber, a switchable chamber capableof being switched between atmosphere and vacuum for carrying the sampleinto and out of the vacuum processing chamber, a cassette supportingmeans for supporting a plurality of cassettes capable of housingsamples, a carriage means capable of moving vertically for taking out asample from a given cassette on the cassette supporting means, a controlmeans performing carriage control for carrying the sample taken out ofthe given cassette via the carriage means, the switchable chamber andthe vacuum carriage means into the vacuum processing chamber, and forcarrying the processed sample out of the vacuum processing chamber, anda waiting cassette supporting means capable of supporting a waitingcassette for preventing the processed sample from being mixed with theunprocessed sample.

According further to the above vacuum processing apparatus of thepresent invention, the waiting cassette supporting means is disposed inatmosphere and capable of supporting the waiting cassette for housingthe processed sample to be put in waiting. According to the vacuumprocessing apparatus of the present invention, the waiting cassettesupporting means is disposed in atmosphere and capable of supporting thewaiting cassette for housing the unprocessed sample to be put inwaiting.

According to the vacuum processing apparatus of the present invention,the waiting cassette supporting means is disposed in vacuum and equippedwith a waiting chamber for housing the processed sample to be put inwaiting.

According to the vacuum processing apparatus of the present invention,the waiting cassette supporting means is capable of supporting a waitingcassette for housing either the processed sample or the unprocessedsample to be put in waiting until all the unprocessed samples arecarried out of the given cassette.

According further to the present vacuum processing apparatus, thewaiting cassette supporting means is disposed in atmosphere and capableof being moved either vertically or horizontally.

According to another aspect of the invention for solving theabove-mentioned problems, the invention provides a vacuum processingmethod comprising the steps of taking out a sample from a given cassetteplaced on a cassette supporting means, carrying the sample into a vacuumprocessing chamber via a chamber capable of being switched betweenatmosphere and vacuum, and subjecting the sample to vacuum processing,characterized in subjecting the sample to vacuum processing with eitherthe unprocessed sample or the processed sample put in waiting in awaiting cassette.

According to the above-mentioned vacuum processing method of the presentinvention, the vacuum processing of the sample is performed with theprocessed sample put in waiting in the waiting cassette disposed inatmosphere. According to another aspect of the present vacuum processingmethod, the vacuum processing of the sample is performed with theunprocessed sample put in waiting in the waiting cassette disposed inatmosphere.

According further to the vacuum processing method of the presentinvention, the vacuum processing of the sample is performed with theprocessed sample put in waiting in a waiting chamber disposed in vacuum.

According further to the vacuum processing method of the presentinvention, the vacuum processing of the sample is performed with eitherthe processed sample or the unprocessed sample put in waiting until allthe unprocessed samples are carried out of the given cassette.

As explained, the present invention provides a method and apparatus forreducing the deterioration of yield factor without reducing theoperating rate by preventing the unprocessed wafers and the processedwafers from being mixed in atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the construction of the vacuum processingapparatus;

FIGS. 2A-2J show operation of the vacuum processing apparatus accordingto a first embodiment; and

FIGS. 3A-3J show operation of the vacuum processing apparatus accordingto a second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Now, the preferred embodiments of the present invention will bedescribed. FIG. 1 shows the structure of the apparatus according to thepresent invention. A vacuum processing apparatus 1 comprises a pluralityof vacuum processing chambers 7-1, 7-2, 7-3, hereinafter generallyreferred to as vacuum processing chamber 7, for subjecting samples 2-1,2-2, 2-3, 2-4, 2-5, hereinafter generally referred to as sample 2, tovacuum processing, a vacuum carriage means 8 for carrying samples 2 intoand out of the vacuum processing chambers 7, switchable chambers 9-1,9-2, hereinafter generally referred to as switchable chamber 9, that canbe switched between atmosphere and vacuum for carrying samples 2 intoand out of the vacuum processing chamber 7, cassette supporting means10-1, 10-2, 10-3, hereinafter generally referred to as cassettesupporting means 10, for supporting plural cassettes 3-1, 3-2, 3-3,hereinafter generally referred to as cassette 3, capable of housingsamples 2, a carriage means 4 capable of moving vertically and takingout a sample 2 from a given cassette on the cassette supporting means, acontrol unit 11 performing carriage control of the carriage means 4 andthe vacuum carriage means 8 for carrying the sample 2 stored in thegiven cassette via the carriage means 4, the switchable chamber 9 andthe vacuum carriage means 8 into the vacuum processing chamber 7 and forcarrying the processed sample out of the vacuum processing chamber. Thecontrol unit 11, which is configured so as to operate in the manner aslater described in connection with FIGS. 2A-2 and FIGS. 3A-3J, is of atype known in the prior art, as exemplified by U.S. Pat. No. 6,451,118,issued Sep. 17, 2002 to Garriga, which describes computer control foroperating wafer handling and processing apparatus in a desired manner.According to the present invention a waiting cassette 5 is newlydisposed in the atmosphere for temporarily storing the unprocessedsample or the processed sample to be put in waiting under the control ofthe control circuit 11, and a waiting chamber 6 for temporarily storingthe processed sample in vacuum. The number of hands equipped to thevacuum carriage means 8 and the atmospheric carriage means 4 is notlimited to one.

According to a first embodiment of the invention, under control of thecontrol unit 11, a first sample 2-1 taken out of cassette 3-1 by thecarriage means 4 disposed in atmosphere is carried via the switchablechamber 9-1 and the vacuum carriage means 8 into the vacuum processingchamber 7-1, and there the sample is subjected to an etching process. Inan example where the plural vacuum processing chambers 7 are operated toperform processing according to the same recipe in a continuous manner,a second sample 2-1 is subsequently carried via the carriage means tothe vacuum processing chamber 7-2 for continuous processing thereof, andsubjected to etching process. Similarly, a third sample 2-1 is subjectedto etching process in the vacuum processing chamber 7-3, as shown inFIGS. 2A-2D. Thereafter, all the unprocessed samples left in thecassette 3-1 are sequentially carried via the carriage means 4 into thewaiting cassette 5 disposed in the atmosphere, starting from the n-thcassette and sequentially in descending order thereof if the number ofsamples housed in the cassette is n, as shown in FIGS. 2E-2F. When allthe unprocessed samples are removed from cassette 3-1, the processedsamples 2-1 in the vacuum processing chamber 7-1 are returned to thecassette 3-1, and thus, the unprocessed samples and processed samplesare prevented from being stored in mixture in a single cassette, asshown in FIGS. 2G-2J.

The waiting cassette 5 desirably has a capacity to store not less thann-m samples, if the number of vacuum processing chambers operatedaccording to the above-described operation is m. For example, if twocassettes are continuously processable in the process for manufacturingproducts, the waiting cassette is designed to have a capacity to storesamples from plural cassettes, and is capable of moving in the verticalor horizontal direction. If the waiting cassette 5 is disposed withinthe range of movement of the carriage means (atmospheric robot) 4, thecassette can be in a fixed state and the movement mechanism can beomitted. According to some processing operations, the carriage controlcan be performed without deteriorating throughput by starting processingof a first processable sample without storing the first sample in thewaiting cassette.

In other words, according to the present embodiment, the vacuumprocessing apparatus is equipped with plural vacuum processing chambersfor subjecting samples to vacuum processing, a vacuum carriage means forcarrying samples into and out of the vacuum processing chamber, aswitchable chamber capable of being switched between atmosphere andvacuum for carrying samples into and out of the vacuum processingchamber, a cassette supporting means for supporting plural cassettescapable of housing samples, a carriage means capable of moving in thevertical direction and taking out samples from a given cassette on thecassette supporting means, and a control means performing carriagecontrol for carrying the sample stored in the given cassette via thecarriage means, the switchable chamber and the vacuum carriage meansinto the vacuum processing chamber and for carrying the processed sampleprocessed in the vacuum processing chamber out of the chamber, whereinthe vacuum processing apparatus is further equipped with a waitingcassette supporting means for supporting a waiting cassette thatprevents the processed samples and the unprocessed samples from beingmixed. The waiting cassette supporting means disposed in the atmosphereis capable of supporting the waiting cassette for storing theunprocessed samples to be put in waiting.

According to embodiment 1, the unprocessed samples were storedtemporarily in the waiting cassette, but the present invention is notlimited to such example. According to embodiment 2, the unprocessedsamples 2 stored in the cassette 3 are carried to the vacuum processingchamber 7 sequentially in order and subjected to processing, as shown inFIGS. 3A-3J, by the carriage means 4 and the carriage means 8 ascontrolled by the control unit 11. The samples having been processed inthe vacuum processing chamber are temporarily stored in the waitingcassette 5, as shown in FIGS. 3E-3I. Then, when the carriage controldetermines that all the unprocessed samples in the cassette 3 have beencarried out, the processed samples are carried out of the waitingcassette and returned to the original cassette 3, as shown in FIGS. 3Iand 3J. In this case, throughput will not be deteriorated if the samplesare started to be carried out when it is determined that all theunprocessed samples have been carried out of the cassette 3, and notwaiting until all the processed samples are housed in the waitingcassette 5. In other words, according to the present embodiment, andtherefore, according to the present invention, the waiting cassettesupporting means disposed in the atmosphere is capable of supporting awaiting cassette housing the processed samples to be put in waiting.

In order to reduce the reaction of any residual corrosive gas adhered tothe processed sample with moisture etc. in the atmosphere that mayaffect the ambient surroundings, it is preferable to provide a purgingmechanism for performing inert gas replacement of the waiting cassette5. The purging mechanism introducing inert gas into the waiting cassettefrom the exterior or from above the waiting cassette will effectivelyimprove the environmental atmosphere inside the cassette. Further, anexhaust mechanism can be provided to the lower area of the waitingcassette. Moreover, a door can be disposed on the waiting cassette 5that is closed when the carriage means 4 is not operated with respect tothe waiting cassette 5, so as to achieve more effective results by theinert gas replacement.

Embodiment 3 is an example adopting a waiting chamber 6 disposed invacuum. After processing the sample 2 taken out of the cassette 3 in thevacuum processing chamber 7, the processed sample 2 is temporarilystored in the waiting chamber 6. Similar to embodiment 2, the presentembodiment is equipped with a carriage means capable of determining thatall the unprocessed samples have been taken out of the cassette 3, andthe samples in the waiting chamber 6 are sequentially carried back tothe original cassette 3. By providing a waiting chamber in vacuum, thesample is prevented from having its surface exposed to the atmosphere,so the affect of corrosion or other causes that may deteriorate theyield factor can be reduced.

In other words, according to the present embodiment, a waiting cassettesupporting means is disposed in vacuum and equipped with a waitingchamber for storing the processed samples to be put in waiting.

According to the embodiments described above, the vacuum processingapparatus is equipped with a waiting cassette supporting means capableof supporting a waiting cassette housing either processed samples orunprocessed samples to be put in waiting until lot processing iscompleted.

Furthermore, according to the vacuum processing apparatus, the waitingcassette supporting means is disposed in atmosphere, and capable ofbeing moved either vertically or horizontally. Thus, if the unprocessedsamples are taken out from plural cassettes, the processed orunprocessed samples can be sorted and stored in the waiting cassettebased on the cassettes that the samples were originally taken from.

In each of the above-mentioned embodiments, the apparatus was equippedwith either a waiting cassette 5 disposed in atmosphere or a waitingchamber 6 disposed in vacuum, but the apparatus can be equipped withboth.

As explained, according to the present invention, the deterioration ofyield factor caused for example by corrosion can be reduced withoutdeteriorating the operation efficiency, by preventing the unprocessedsamples and the processed samples from being mixed in atmosphere.

1. A vacuum processing apparatus comprising: a plurality of vacuumprocessing chambers for subjecting a sample to vacuum processing; avacuum carriage which carries the sample into and out of the vacuumprocessing chamber; a switchable chamber capable of being switchedbetween atmosphere and vacuum for carrying the sample into and out ofthe vacuum processing chamber; a cassette supporter which supports aplurality of cassettes capable of housing samples; a waiting cassettesupporter capable of supporting in atmosphere a waiting cassette thatdiffers from the cassette supported on the cassette supporter; anatmospheric carriage capable of moving vertically for taking out asample from a given cassette supported on the cassette supporter; and acontroller performing control for carrying an unprocessed sample takenout of the given cassette by the atmospheric carriage via the switchablechamber and the vacuum carriage into the vacuum processing chamber, forcarrying the processed sample taken out of the vacuum processing chamberto the waiting cassette, and for returning the processed sample from thewaiting cassette to the given cassette in a state where no unprocessedsample exists in the given cassette while processing a sample in thevacuum processing chamber.
 2. A vacuum processing apparatus comprising:a plurality of vacuum processing chambers for subjecting a sample tovacuum processing; a vacuum carriage which carries the sample into andout of the vacuum processing chamber; a switchable chamber capable ofbeing switched between atmosphere and vacuum for carrying the sampleinto and out of the vacuum processing chamber; a cassette supporterwhich supports a plurality of cassettes capable of housing samples; awaiting cassette supporter capable of supporting in atmosphere a waitingcassette that differs from the cassette supported on the cassettesupporter; an atmospheric carriage capable of moving vertically fortaking out a sample from a given cassette supported on the cassettesupporter; and a controller performing control for carrying anunprocessed sample taken out of the given cassette by the atmosphericcarriage to the waiting cassette, for carrying an unprocessed sample inthe waiting cassette or an unprocessed sample in the given cassette viathe switchable chamber and the vacuum carriage into the vacuumprocessing chamber, and for carrying the processed sample processed inthe vacuum processing chamber into the given cassette from where thesample was taken out in a state where no unprocessed sample existstherein, while processing a sample in the vacuum processing chamber. 3.A vacuum processing apparatus comprising: a plurality of vacuumprocessing chambers for subjecting a sample to vacuum processing; avacuum carriage which carries the sample into and out of the vacuumprocessing chamber; a switchable chamber capable of being switchingbetween atmosphere and vacuum for carrying the sample into and out ofthe vacuum processing chamber; a cassette supporter which supports aplurality of cassettes capable of housing samples; a waiting cassettesupporter capable of supporting a waiting cassette that differs from thecassettes supported on the cassette supporter; an atmospheric carriagecapable of moving vertically for taking out a sample from a givencassette supported on the cassette supporter; and a controllerperforming control for carrying an unprocessed sample taken out of thegiven cassette by the atmospheric carriage via the switchable chamberand the vacuum carriage into the vacuum processing chamber, for carryingthe processed sample taken out of the vacuum processing chamber to thewaiting cassette, and for returning the processed sample from thewaiting cassette to the given cassette in a stage where no unprocessedsample exists in the given cassette while processing a sample in thevacuum processing chamber.
 4. A vacuum processing apparatus comprising:a plurality of vacuum processing chambers for subjecting a sample tovacuum processing; a vacuum carriage which carries the sample into andout of the vacuum processing chamber; a switchable chamber capable ofbeing switched between atmosphere and vacuum for carrying the sampleinto and out of the vacuum processing chamber; a cassette supporterwhich supports a plurality of cassettes capable of housing samples; awaiting cassette supporter capable of supporting a waiting cassette thatdiffers from the cassette supported on the cassette supporter; anatmospheric carriage capable of moving vertically for taking out asample from a given cassette supported on the cassette supporter; and acontroller performing control for carrying an unprocessed sample takenout of the given cassette by the atmospheric carriage to the waitingcassette, for carrying an unprocessed sample in the waiting cassette oran unprocessed sample in the given cassette via the switchable chamberand the vacuum carriage into the vacuum processing chamber, and forcarrying the processed sample processed in the vacuum processing chamberinto the given cassette from where the sample was taken out in a stagewhere no unprocessed sample exists therein, while processing a sample inthe vacuum processing chamber.